Here, 'assault' is the military term: the final advance over the last 50-100 m to take an objective held by the enemy. An assault rifle is a military rifle which can be fired selectively either semi-automatically or fully automatically. It uses a relatively low-power cartridge and is generally designed for low-cost production, light weight, and use by minimally trained personnel. In the US, all these are subject to the National Firearms Act of 1934, and to state laws on automatic weapons. However, some state and federal laws also define many other semiautomatic rifles as "assault rifles".
A military rifle intended purely for one-man operation and equipped to provide both semiautomatic or full-automatic fire by means of a selector switch or other fire-control device. Today's assault rifles are typified by the Soviet AK 47 and the U. S. M 16. They are chambered for an intermediate cartridge, have barrels under 20 inches, make extensive use of plastics and stampings, use gas operation and locked breeches, have magazine capacities of 20 to 30 rounds, weigh from six to 10 pounds and are quite compact.
any of the automatic rifles or semiautomatic rifles with large magazines designed for military use
a fully automatic infantry weapon, while the civilian version of the same is merely a semi-automatic rifle, just like the one that Dad used for deer hunting
a long barrel firearm with a rifled bore, designed to be fired from the shoulder
a military rifle capable of firing more than one round when the trigger is pulled - essentially a light machine gun
a rifle used by militaries
a type of automatic weapon
By U.S. Army definition, a selective-fire rifle chambered for a cartridge of intermediate power. If applied to any semi-automatic firearm regardless of its cosmetic similarity to a true assault rifle, the term is incorrect.
An assault rifle is a selective fire rifle or carbine firing ammunition with muzzle energies intermediate between those typical of pistol and battle rifle ammunition. The ammunition is supplied from an interchangeable box magazine. Assault rifles are categorized between light machine guns that are intended more for sustained automatic fire in a support role, and smaller submachine guns that fire a handgun cartridge rather than a rifle cartridge.